Reliability and Responsiveness of the Hand20 Questionnaire in Thumb Carpometacarpal Joint Osteoarthritis: A Pilot Study

Background Thumb carpometacarpal (CMC) joint osteoarthritis significantly impairs hand function and quality of life, particularly in older adults. Reliable patient-reported outcome measures (PROMs) are essential for assessing disease impact and evaluating treatment efficacy. The Hand20 questionnaire, widely used for upper extremity conditions, has demonstrated strong reliability and responsiveness. However, its specific utility in thumb CMC joint osteoarthritis remains unexplored. Methods This retrospective study included 20 patients diagnosed with thumb CMC joint osteoarthritis. Hand20 scores were collected at baseline, three months, and six months. Test-retest reliability was evaluated using the intraclass correlation coefficient (ICC) from a mixed-effects model. Responsiveness was assessed using the effect size (ES) and standardized response mean (SRM). Paired t-tests were used to analyze changes in scores over time. Results The mean Hand20 score decreased from 33.50 at baseline to 18.77 at three months and 15.93 at six months. The ICC was 0.672 (95% confidence interval {CI}: 0.406-0.823), indicating moderate-to-good reliability. Responsiveness was moderate at three months (ES: -0.650, SRM: -0.708) and large at six months (ES: -0.776, SRM: -0.940). Paired t-tests showed significant reductions in Hand20 scores over time, confirming progressive improvements ( <i>p</i> < 0.005). Conclusion The Hand20 exhibited moderate reliability and substantial responsiveness, underscoring its utility in evaluating treatment outcomes for thumb CMC joint osteoarthritis. Its ease of administration and sensitivity to clinical changes make it a valuable tool for clinicians. Further research with more diverse populations is needed to confirm these findings and explore their broader applicability.